


Training

by Sin_Cognito



Category: Undertale (Video Game)
Genre: Cherryberry - Freeform, M/M
Language: English
Status: Completed
Published: 2018-08-24
Updated: 2018-08-24
Packaged: 2019-07-02 00:58:00
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,888
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15785694
Author URL: https://archiveofourown.org/users/Sin_Cognito/pseuds/Sin_Cognito
Summary: It all begins with Blue asking Boss to train him.And it all ends with cherryberry.





	Training

**Author's Note:**

  * For [MeGaLoTrash](https://archiveofourown.org/users/MeGaLoTrash/gifts).



> This is a late birthday gift for the awesome, incredible, super talented and sweet megalotrashy! I've been holding on this fic for a long time now (I wrote it in March I think?) and was waiting for their birthday that I MISSED BECAUSE I WAS HAVING INTERNET ISSUES. Fuck my internet.
> 
> Anyway, I really hope you like it Trashy! You're an awesome friend and I luv you so much and I send you smooches!!! ♥♥♥

Red watched with an amused smile as Blue followed Boss to the kitchen. He was currently sitting on the couch with Swap, each with their favorite condiments in their hand, and they had been enjoying the show for about an hour now. It was way better than TV.

"I DO NOT THINK IT IS A GOOD IDEA, BLUE," he heard Boss' voice say disapprovingly.

"PLEASE FELL! I NEED TO TRAIN IF I WANT TO JOIN THE ROYAL GUARD!" Blue pleaded, and Red could picture his cute little face morphing into an irresistible pout. Irresistible for him, but not for Boss apparently.

"THEN GO TRAIN BY YOURSELF. DEPENDENCY TO OTHERS IS A HUGE FLAW FOR SOMEONE WHO WANTS TO BE A GUARD," Boss shot back as he came back to the living room, Blue still on his tailbone.

Red couldn't help a small laugh, though he did his best to hide it behind a cough. Blue's newest and arguably best idea was to ask Boss to train him to be a guard. It was logical since Boss was captain in second in his and Red's home universe, but Red knew his brother hated training novices with a passion. Too weak, too whiney. A total waste of time.

But Red was crushing hard on Blue, and it was clear Boss was trying his best not to reject the small skeleton too hard and crush his dreams. He knew Red would never forgive him if he did.

"BUT I NEED SOMEONE TO HELP ME WITH CLOSE COMBAT TECHNIQUES! I CAN'T DO IT ON MY OWN!" Blue had a point there, and Boss stopped, considering it.

"THEN TRAIN WITH YOUR BROTHER," he retorted.

"COME ON, FELL. WE BOTH KNOW MY BROTHER IS EVEN LAZIER THAN YOURS."

"hey. i can hear you you know," Swap interjected flatly from the couch, as if to prove what Blue had just said. There weren't many things Swap wished to avoid more than his brother's training.

Red couldn't help blushing as he imagined himself as Blue's training partner, the small body of the petite skeleton pined under his bigger body and Red bending down to lick at-

Wow calm down Red.

"FELL, PLEAAAAAASE!" Blue pleaded again. It was clear Boss was running out of excuses and Blue apparently knew exactly what to say to Boss' silence, "I Just Wanted To Be Trained By The Best And Greatest Royal Guard That Has ever Been... But I Guess I'll Just Have To Ask Alphys."

Red heard Swap snicker next to him.

"Hmpf. Very Well," Boss relented. "I Guess I'll Just Have To Train You Myself Then. BUT FIRST I WANT TO TEST YOU. I WILL NOT WASTE MY PRECIOUS TIME TRAINING A WIMP THAT CAN'T HANDLE IT. UNDERSTOOD?"

"YES! THANK YOU!!" Blue shouted excitedly, ready to jump at Boss and hug him if the tall skeleton hadn't stopped him.

(Good thing Boss had, because Red didn't know how he would have reacted if they had hugged right in front of him.)

"NOW LET'S GO! I WANT TO GET IT OVER WITH AS QUICKLY AS POSSIBLE!" Fell commanded, already opening the door for Blue to follow him.

"YES SIR!"

It was only when the two were about to disappear from his sight that Red realized he was about to miss an occasion to admire his crush train with his brother, something he had been dreaming of since coming to this universe. But it was too late, and he had no good excuse to join them now. What could he say to Blue that would be believable and not make him look like a total moron? He was internally panicking and almost didn't hear Swap cough quietly next to him.

"red? you want to go watch them train?" And seeing the hopeful but reluctant look on Red's face, he added with a wink, "you can tell Blue i insisted."

"duuuude! yes! thanks bud!" Red exclaimed as he gave a playful hug to his friend. Of course Swap would've known Red would want to go see them, it wasn't exactly a secret that Red was pining for Blue.

"ah ah! i'm not doing it for free! you'll have to sneak in one of those big weed mead bottle from your universe next time you come."

"i'll buy you three!"

"deal." Swap then got on his feet, ran to the door and shouted, "guys!! wait! red and i are coming!"

* * *

 

Blue let out a soft white puff of frozen air as he caugth his breath. He was visibly exhausted, barely standing up and his shoulders were sagged forward. He wiped a thin coat of sweat from his forehead and adjusted his stance. Training wasn't over.

"TRAINING IS OVER," Boss said in a final tone.

"WHA-? NO!"

"BLUE, IT HASN'T EVEN BEEN 10 MINUTES AND I CAN ALREADY TELL YOU'RE TOO WEAK TO UNDERGO MY SPECIAL TRAINING," Boss retorted, already turning around to go home.

"WEAK?!" Blue repeated, offended. "I'M NOT WEAK! TAKE THIS!" And he ducked forward and kicked Boss' legs, sending him flying in the snow. He looked as surprised as Boss himself to have achieved that and couldn't supress his laughter.

Boss stood up from where he had fallen, a thick layer of snow coating his body, his skull a bright red contrasting with the whiteness of the snow. He stomped his feet on the ground and shouted angrily. "BLUE! WHAT THE FUCK WAS THAT!"

"L-LANGUAGE!" Blue admonished, though there was no real threat with how he was still wheezing in laughter. He managed to get his breath under control again as he calmed down enough to speak. "BUT SEE? WITH THE PROPER TRAINING OF THE GREAT AND TERRIBLE PAPYRUS, I'M SURE I COULD DO EVEN BETTER!"

"BECAUSE YOU THINK I'M STILL GONNA TRAIN YOU AFTER THAT?!" Boss yelled.

"WHAT? DON'T TELL ME YOU'RE THE KIND OF MONSTER TO GIVE UP JUST AFTER A SINGLE BLOW? OR..." Blue audibly gasped in shock, "Maybe You're Just Not up To The task?"

The tall skeleton actually seemed to consider it, his brow crunched in concentration for a while. "I Suppose I Could Train You Since You're Not As Weak As I Originally Thought."

'Good' Blue thought. 'The First Part Of The Plan Is A Success...'

* * *

 

Blue was different lately. Red could tell because the small skeleton was all he could think of. So Red was able to notice any change in his mood, any small difference in his behavior.

Of course, the most obvious change was in Blue's physical appearance. After undergoing Boss' training for 3 months, anyone would gain some muscles, and Blue was no exception. On the rare occasions when Red let himself be a creep and peep on Blue's naked body when he was taking a shower, he could see the evidence of the once chubby skeleton getting... buffier. And yet, Blue managed to keep those beautiful curves that would keep Red awake at night, jerking off silently with the quietness of the night as his only company, until morning came by and Red had to pretend everything was okay and Blue was just a friend.

But the more noticeable difference was in Blue's behavior. He had gotten _really_  touchy-feely with Red, and while he definitely didn't mind, it was trickier than ever not to just pop a boner whenever Blue crawled on his back and gave him a surprise hug. At some point, Red even thought Blue had realized Red had more than friendly feelings about him and was teasing him, but their only conversations were about the damn guard or Boss' training. Red was at the same time relieved and frustrated by Blue's obliviousness, how adorable it might be.

But it was only when Boss had asked to speak to Red privately that it really occurred to him that Blue's change in behavior was more than obvious, and not only for him. If even Boss had noticed, that really meant something wasn't right. Unfortunately, asking Swap had led to nowhere, the lanky skeleton was too deep in his blind admiration for his brother to think anything could be wrong with Blue. So Red had no choice but to listen to Boss' advice, who told him (or rather commanded) to go talk to Blue and see if everything was fine. Apparently, Boss had already tried to brush the subject with Blue, but the small skeleton had assured him everything was okay. But when Boss attempted to shift the conversation to how Blue was behaving around Red specifically, he had clammed up completely, albeit very politely as always, and said if Red was bothered that he could just come talk to Blue.

So that left Red even more confused. Had he done something to Blue? He couldn't recall. Then again, it wasn't like Blue was avoiding him, quite the contrary even. So that meant at least Blue wasn't angry at him. But then what could have caused such a change in his behavior? Red tried his damnest best not to get his hopes too high. His universe had taught him how hard and unpleasant the fall was.

First he tried to find an appropriate moment to talk to Blue, which happened to be quite difficult with either Swap or Boss always there doing this or that in the house. There were instances when Swap wasn't present, at Muffet's or the King knows where, but Blue was usually out training with Boss during those times. Blue invited Red for a sleepover one time, and Red almost thought it was his chance to be alone with Blue and talk to him because neither Boss nor Swap could be present that night. But when he arrived and saw Alphys and Undyne helping Blue set up pillows and blankets in the living room, he knew it wasn't going to happen.

It took another whole month for Red to find the right moment and when it finally came, he nearly let it escape, being totally unprepared for it. Red was lazily watching television with Swap when the lanky skeleton asked him if he wanted to go to Muffet's. Red declined, mainly because he wasn't a fan of Muffet's pastries (they lacked mustard in his opinion), but also because he wanted to wait for Blue to return from his training with Boss. The two had gone training before Red had come so he hadn't even seen Blue today and the small skeleton was like a drug to Red. If he didn't have his daily dose of chubby-buffy cuteness, he would feel terrible withdrawal effects.

When only Blue came back from training however, Red was surprised not to see Boss with him. Blue quickly explained Red's brother had had an urgent call and had to go back to Underfell, calling training off for today and letting Blue do whatever he wanted with his evening. He then hurried to the shower, slamming the door behind him and leaving Red on his own in the living room. Red was about to go tell him through the door he was going home when he realized it was his chance to have a one on one conversation with Blue, and finally learn if he had done something that had upset Blue. So he went to the couch and waited for Blue to be finished.

He gave another 5 minutes for Blue to change before going to his bedroom door and knock.

"blue? i wanna talk," he said simply.

"SURE! COME IN!"

Red steadied himself with a long sigh before pushing the door open, only to sputter at the sight of Blue standing in front of his mirror. He was half naked. Were 5 minutes not long enough to put on a fucking tee shirt?! Once again, Red didn't _really_  mind seeing Blue's perfect body, his ecto-flesh still wet and glistening in the dim room.

Still, it didn't stop Red from blushing hard.

"WHAT IS IT RED?" Blue prompted him when Red's silence stretched for too long. "YOU SAID YOU WANT TO TALK, IS THERE SOMETHING ON YOUR MIND?"

Red snapped out of it, it really wasn't the time to be distracted by Blue's perfect body and pop a boner. "yeah uhh... i noticed you-... _we_  noticed with Boss that lately you've been... more... err... you've been very... fuck how can i put this?"

Without waiting for the rest of Red's sentence, Blue _still half naked_  jumped into Red's arms and wrapped him in a powerful hug. "LANGUAGE, RED! AND DON'T WORRY, YOU CAN TELL ME ANYTHING!"

Fuck.

Blue's little face was so cute Red couldn't stop himself in time. He felt his magic conjure a cock with a speed that would be embarrassing if he wasn't so focused on not rubbing it to Blue's leg. "you've been very... this," he said lamely as he gesticulated to how Blue was wrapped around him.

"CUTE?" Blue asked, eyelights morphing into little stars.

"no, i mean, yeah! you're cute! i-i meant errr... clingy? but not in a wrong way!" Red was a blabbering mess as red as his nickname. This conversation was going nowhere and he was just making a fool of himself. Fuck.

"Oh. Does That Bother You?" Blue asked, disappointment clear in his tone, and Red loathed himself in that moment, for even letting Blue think he didn't enjoy his affections.

"no! not at all!!! i guess i was just wondering where it came from..."

Blue offered a large smile at Red's words. "REALLY?! YOU DON'T MIND?" And as he asked, he tightened his hug around Red.

"you kidding me? i love 'em! seriously blue, you give the best hugs in the multiverse." Red had the feeling Blue had somehow dodged his question but it didn't matter why Blue was acting this way. Red was basking in his crush's hugs and that was all that was important. At least now he could indulge without restraint.

He wasn't pepared however to Blue pressing his body against his, Red's forgotten but still very present cock brushing along Blue's pelvic bone through their clothing. He gasped and opened his eyes widely, only then taking in Blue's impish expression.

"Do You Also Like It When I Do That? You Don't Have To Answer, I Can _Feel_  Just How Much You Like It." And Blue locked a leg around Red's right one, making sure to press his pelvis on Red's erection.

"i... can explain," Red tried, though he knew there was no way he could explain.

Blue laughed and brought a hand to Red's cheek. "You Don't Need To. I've Noticed How You Feel About Me. And I Feel The Same," he finally whispered, a light blue blush gracing his cheekbones and making Red lose all mental capacity.

Blue knew Red was in love with him. And Blue reciprocated his feelings. It was more than Red had ever hoped for.

"Uhm Red?" Blue snapped him out of it. "That's Your Cue To Kiss Me."

Oh that Red knew how to do. He bent over, closed his eyesockets and hummed when he felt Blue's mouth open to let him through. He savored the moment his tongue found Blue's and shivered in pleasure when he heard Blue sigh in contentment. All too soon he broke the kiss and gasped, his breath already short. He couldn't stop staring at Blue's hazing eyelights as he gently pushed him toward the bed. He briefly thought maybe Blue would've liked to at least go on a date once before going all the way through with him, but Red couldn't hold back. He had waited way too long. But none of this mattered when Blue clanked their mouths together again, and suddenly they were on the bed, Red on top of Blue and shakingly opening the zipper of his pants.

Red stopped when he felt Blue's arms push his chest. "RED, STOP!"

"what? what? what's wrong? what did i do wrong?"

Red went from pure arousal to pure panic in less than a second. Had he hurt Blue? Was he hurting Blue? Had he somehow misread Blue's signals?

"I Wanna Be On Top!" Blue said in a huff, and Red was relieved he hadn't hurt Blue or anything.

Only then what Blue had just said sank in. "what? you? on top?" And it really wasn't to make fun of Blue, but Red couldn't contain a hearty laugh that shook his whole body. He wiped tears at the corner of his sockets before looking at Blue's face and saw just how serious Blue was. "what, seriously? sorry blue, but there's no way you can top me. you wouldn't be able to tame me, i'm maybe 20 times bigger than you."

Blue smiled at him and the devilish gleam from before was back. "OH I THINK I CAN! I'M REALLY STRONG! LET ME SHOW YOU!"

And Blue took Red's hands into his and turned him over until he was pining Red down. Red struggled for a moment, only to come to the undeniable conclusion that he couldn't move his limbs. Like, at all. Not even by 1 millimeter. He was competely and utterly trapped.

Blue must've noticed the look of realization on his face because he chuckled and bent over until his face was just a breath away from Red's. "Why Do You Think I Asked Your Brother To Train Me?"

Well, Red was screwed.

Litterally.

**Author's Note:**

> Okay so I know I said I had this fic ready since March but it's not completely true. I actually used a prompt Trashy sent me for my 500/600 followers raffle and had it finished, but as time went by I realized that it seemed like Trashy prefers top/dom Blue. Originally, Red was supposed to say 'I'm really strong! Let me show you!', but I decided to change the end to have a more doming Blue. I actually prefer it now!


End file.
